an alumina supported co/ni catalyst was prepared by sol-gel procedure to study the catalytic behavior during fischer-tropsch synthesis in a fixed-bed reactor. the effect of co conversion (10-50%) on hydrocarbon product distribution (ch4, c5+ and c2-c4 olefin selectivities) was studied. selectivity for ch4 decreased, while those of c5+ and olefin selectivities increased with increasing co conver...

Synchronous communication is useful to model multiparty sessions where control for timing events and strong sequentially order of messages are essential to the problem specification. This paper continues the work on multiparty session types initiated by Honda et al. [13] for synchronous communications. It provides a more relaxed syntax of the calculus, multicasting, higher-order communication v...

This article shows how the operational semantics of a language like ORC can be instrumented so that the execution of a program produces information on the causal dependencies between events. The concurrent semantics we obtain is based on asymmetric labeled event structures. The approach is illustrated using a Web service orchestration instance and the detection of race conditions.

Pre-obligations denote actions that may be required before access is granted. The successful fulfillment of pre-obligations leads to the authorization of the requested access. Pre-obligations enable a more flexible enforcement of authorization policies. This paper formalizes interactions between the obligation and authorization policy states when pre-obligations are supported and investigates t...